Since that date, he has been busy making sure Oakland fans won't forget him.
The A's acquired the left-handed-hitting infielder in a trade with the Tigers, as Oakland sent Minor Leaguer Jason Perry to Detroit for Hannahan, who was hitting .295 with the Triple-A Toledo Mud Hens prior to the swap.
Hannahan had just nine at-bats with Detroit in 2006, but since the trade, he has received a chance to play every day for the A's, filling in at third base for a depleted infield.
"I'm just feeling more comfortable every day," Hannahan said. "It's real exciting, to go from not being an invitee for Spring Training to playing third every day. It's made me relax more. Knowing I am going to be in the lineup most days had made the transition easier for me."
Hannahan collected his first Major League hit on Aug. 15, but went just 2-for-15 in his first five games. Since then, he has gone 9-for-26, good for a .346 average during that stretch. He has smacked four doubles, two homers and has driven in seven runs.
"He's done a good job," A's manager Bob Geren said. "He's had some big hits and he's showing good patience at the plate."
Hannahan's first multi-hit game came last Monday in Toronto, where he had two hits, including a big three-run home run, in a 6-4 win.
"He's done a nice job," A's second baseman Mark Ellis said. "He's played a solid third base and he's come up with some big hits."
Injuries, injuries, injuries ... When Geren showed up in the A's dugout for his pregame powwow with the media, he started it off by updating the status of most of the A's that are currently injured.
Geren began by noting that pitcher Rich Harden threw off a mound in Phoenix on Monday, tossing 25 pitches. He said Harden sounded positive and that he would be back in Oakland on Tuesday.
Geren moved to a trio of outfielders in Mark Kotsay, Travis Buck and Chris DeNorfia.
He said Kotsay's back was feeling a little better, but he hasn't resumed baseball activity yet. The manager said Buck and his injured left hamstring were feeling better, but he has yet to resume running. DeNorfia, acquired in a trade with the Reds, is out for this season after undergoing Tommy John elbow surgery, but he is in Oakland on a throwing and hitting program.
Geren then addressed his left side of the infield in third baseman Eric Chavez and shortstop Bobby Crosby. He said Chavez is in Phoenix and is continuing his program as he aims to recover from a stiff back. Crosby got the cast removed from his hand that was broken in a game in Anaheim, and the shortstop is seeing a hand therapist in Southern California.
Dribblers: The A's announced that seven players in the organization will be taking part in the Arizona Fall League that starts on Oct. 9. Pitcher Jay Marshall, who is with the A's, will be joined by right-hander Jeff Gray (Triple-A Sacramento), infielder Jeff Baisley, lefty Jerry Blevins, shortstop Cliff Pennington, catcher Anthony Recker and right James Simmons, all from Double-A Midland. Simmons was the A's first pick in this year's First-Year Player Draft. ... In a very odd statistic, the A's are showing a penchant for success in the middle of the week and not much of one for the weekends. Oakland is 50-40 in games played between Monday and Friday, and is just 15-27 in games played on Saturdays and Sundays.
Up next: A's righty Chad Gaudin (10-9, 4.12 ERA) will oppose Blue Jays righty Jesse Litsch (5-6, 3.44) at 7:05 p.m. PT on Tuesday.
Matt Smith is an associate reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.